Two cycle engine



y 1935. c. F.VKETTERING 2,007,608

TWO-CYCLE ENGINE Filed May 27, 1951 gwuentoz Patented July 9, 1935UNITED sTATEs PATENT OFFICE TWO CYCLE ENGINE Charles F. Kettering,Dayton, Ohio, assignor, by

mesne assignments, to General Motors Gorporation, Detroit, Mich., acorporation of Delaware Application May 27, 1931, Serial No. 540,235

14 Claims. (01. 123-65) This invention relates to two-cycle internalchamber 20. The combustion chamber has an combustion engines and hasparticular reference attenuated branch portion 22 and a rotary valve toa system of manifolding whereby the idling 24 is mounted at the endthereof to control the and low running speeds of the engine is improved.admission of carburetted gas from the carburetor In two-cycle enginesequipped with a blower 26. A spark plug 28 is positioned at an'enlarged5 and an attenuated firing chamber, difiiculty has portion of thecombustion chamber 20 immedibeen experienced in obtaining goodperformance ately beyond a rotary valve 30 shown as posiat idling and atlow speeds. It is the purpose tioned at the top of the combustionchamber 20 of the present invention to equip two-cycle enin the head l8;A second spark plug 32 is posigines with a manifolding system in whichthe cartioned in the attenuated passage 22 immediately 10 buretted fuelis localized adjacent the spark plug beyond the valve 24. in anattenuated or relatively long and narrow The usual water circulatingsystem of the enportion of the combustion chamber so that better glue isindicated at 34. ignition and combustion is obtained. When the A riser36 leads from the carburetor 26 and engine is running at higher and/orat full speeds, delivers into, the inlet 38 of a blower 40. The 15 thelocalized .charge and attenuated combustion blower may be of anysuitable type and in the chamber are no longer needed and may even bedrawing is illustrated as comprising the two out out of the system. Whenthese higher speeds figure 8 rotors 42 driven by suitable gearing 44.are reached, the carburetted fuel is passed A chain 46 connects theblower to the crankshaft through asecond pipe or manifold and led to thein any suitable way. The outlet 48 of the blower 20 firing chamber incloser proximity to the pisdelivers into the pipe or riser 50 connectedat ton. At higher speeds ignition and combustion its other end to thepassage in the head I8 leadis notso great a problem because of thepresence ing to the rotary valve 24. The riser 50 has the of morecarburetted fuel and less burned gases so branch 52 connected as at 54to a pipe or manithat it is unnecessary to localize the charge of fold56 connected as at 58 to the head portion I8 25 carburetted fuel.leading to the valve 30.

The second or high speed branch or manifold is The branch riser 50 isprovided with a throtcontrolled by a throttle valve which in turn isoptle valve 60 having an arm 62 connected to a erated by a suitablegovernor. The greater the suitable operating rod (not shown) and adaptedspeed, the more will the governor open the to be manually operated. 30

v throttle valve to allow a greater fiow of car- The manifold 56 has athrottle valve 64 having buretted fuel, and at high speeds the throttleis a lever arm 66. A rod 68 connects the lever arm fully open. When thespeed is low the governor to a suitable governor 10, in the presentinstance will not open the throttle, thereby forcing the shown to be ofthe fly-ball type. The governor 5 carburetted fuel to flow through afirst branch or m is driven from the crankshaft to the engine, pipe andenter the attenuated combustion chamsuch as by the gearing I2, in anysuitable way. her and thereby cause a localization of the fuel Thegovernor operates to open the throttle valve charge about the sparkplug, thereby insuring 64 with an increase in speed and to close it withproper ignition and combustion. A a decrease in the speed of the engine.0 On the drawing, Figure l is a sectional view The operation of thedevice is as follows. At through the pipes or manifolds and one cylinderlower speeds, the operator cracks the throttle 60 of a multi-cylindertwo-cycle internal combusa suitable amount so that the carburettedmixtion engine with the governor shown in a more or ture will ascend inthe pipe or riser 50 past the less schematic relation. valve 24 into theattenuated passage 22 of the 5 Figure 2 is a plan view of the engine.combustion chamber. When the piston has Referring to the drawing, thenumeral 2 indireached the bottom of its stroke, the blower will cates amulti-cylinder internal combustion enforce the carburetted fuel into thecombustion gine as a whole. The engine has the crankcase chamber andsupply the new charge. On its up- 4 and engine block 6, while one of thecylinward stroke, the piston will compress the gases ders is indicatedat 8. The usual piston l0, conand force them backward into the firingcham- 50 nected as at I2 to the connecting rod l4, operber. Owing to thefact that the main portion of ates in the cylinder in the usual way.Exhaust the chamber 20 will have a large amount of ports for thecylinder are indicated at I6. Over burnt gases therein, the spark plug28 will be the cylinder block 6, there is positioned the head unable togive proper ignition. However, the I8 in which there is formed thecombustion charge about the spark plug 32 will largely be 55 carburettedfuel so that the charge may be said to be localized about the spark plug32. The fuel is therefore readily ignited and good combustion obtained.The attenuated passage 22 is relatively small and gives good performanceof the engine at slow speeds and idling. As the speed increases, thequantity of fuel supplied to the combustion chamber is much greater sothere is but little need for a localized charge. At higher speeds, thegovernor 10 will crack the throttle 64 to open the manifold 56 and allowthe charge to pass to the valve 30 and directly into the firing chamberto be ignited by the spark plug 28. The valve 24, spark plug 32, andattenuated chamber 22 will, of course, still be operating but theirpresence is not necessary at the high speeds.

When the engine slows down, the governor will gradually close thethrottle 64 to again force the charge to enter past the valve 24 intothe chamber 22.

I claim:

1. In a two-cycle engine having an interrelated blower and a.carburetor, an intake pipe leading from the blower to the combustionchamber of the engine, means to control the flow of fuelthrough saidpipe, a spark plug immediately beyond said means, a second intake pipeleading from the blower to the engine, means in said second pipe tocontrol the flow of fuel therethrough, and speed responsive mechanism tooperate said last named control means.

2. In a multi-cylinder two-cycle engine having an interrelated blowerand a single carburetor, an intake pipe leading from the blower to thecombustion chamber of the engine, a throttle for controlling the flow offuel through said pipe, a valve in said pipe to control the admission offuel to the combustion chamber, fuel ignition means in the combustionchamber immediately beyond said valve, a second intake pipe leading fromthe first pipe to the combustion chamber, a throttle in said second pipeto control the flow of fuel therethrough, speed responsive mechanism tocontrol said second mentioned throttle, said means operating to opensaid throttle wider as the speed increases, a valve in said pipe tocontrol the admission of fuel to the combustion chamber, and a secondfuel ignition means in said chamber immediately beyond the second valve.

3. In a two-cycle engine having an interrelated blower and a carburetor,an intake pipe leading from the blower to the combustion chamber of theengine, means to control the flow of fuel through said pipe, a sparkplug immediately beyond said means, a second intake pipe leading fromthe blower to the engine, said carburetor delivering the same quality ofmixture to both intake pipes, and means in said second pipe to controlthe flow of fuel therethrough.

4. In a two-cycle engine having an interrelated blower and a carburetor,an intake pipe leading from the blower to the combustion chamber of theengine, means to control the flow of fuel through said pipe, a sparkplug immediately beyond said means, a second intake pipe leading fromthe blower'to the engine, means in said second pipe to control the flowof fuel therethrough, said carburetor delivering the same quality ofmixture to both intake pipes, and means depending on the speed of theengine to operate said last named means.

5. In a two-cycle engine having an interrelated blower and a carburetor,an intake pipe leading from the blower to the engine, a valve to controlthe flow of fuel through said pipe, a fuel ignition means immediatelybeyond said valve, a second intake pipe leadingfrom the blower to theengine, and means in said second pipe to control the flow of fueltherethrough, said carburetor delivering the same quality of mixture toboth intake pipes, a valve in said second pipe, and fuel ignition meansimmediately beyond said valve.

6. In a multi-cylinder two-cycle engine having an interrelated blowerand a carburetor, an intake pipe leading from the blower to thecombustion chamber of the engine, a throttle for controlling the flow offuel through said pipe, a valve in said pipe to control the admission offuel to the combustion chamber, fuel ignition means in the combustionchamber immediately beyond said valve, a second intake pipe leading tothe combustion chamber, said carburetor delivering the same quality ofmixture to both intake pipes, a throttle in said second pipe to controlthe flow of fuel therethrough, means depending upon the speed of theengine to control said second mentioned throttle, said means operatingto open said throttle wider as the speed increases, a valve in said pipeto control the admission of fuel to the combustion chamber, and a secondfuel ignition means in said chamber immediately beyond the second valve.

'7. In a two-cycle engine having an interrelated blower and acarburetor, an intake pipe leading from the blower to the combustionchamber of the engine, a second intake pipe leading from the blower tothe engine, single means to control the flow of fuel through said pipes,said carburetor delivering the same quality of fuel mixture to bothintake pipes, and a throttle in said second pipe to control the flow offuel therethrough.

8. In combination with a two-cycle internal combustion engine, acarburetor, a blower to draw air through the carburetor, a pipe leadingfrom the blower to the engine, a throttle in said pipe, a valve in saidpipe to control the flow of car-'- bureted air to the engine, fuelignition means in said pipe beyond said valve, a second pipe connectedto the first pipe beyond the throttle valve and leading to the engine, athrottle in said second pipe to control the flow of carbureted airtherethrough, a valve in said second pipe to control the flow ofcarbureted air to the engine, and a second fuel ignition means at theengine beyond the end of the said second pipe.

9. In combination with a two-cycle internal combustion engine, acarburetor, a blower to draw air through the carburetor, a pipe leadingfrom the blower to the engine, a throttle in said pipe, a valve in saidpipe to control the flow of carbureted air to the engine, fuel ignitionmeans in said pipe beyond said valve, a second pipe connected to thefirst pipe beyond the throttle valve and leading to the engine, athrottle in said second pipe to control the flow of carbureted airtherethrough, a valve in said second pipe to control the flow ofcarbureted air to the engine, means to control said second throttle inaccordance with the speed of the engine, and a second fuel ignitionmeans at the engine beyond the end of the said second pipe.

10. In combination with a two-cycle internal combustion engine, acarburetor, a blower to draw air through the carburetor, a pipe leadingfrom the blower to the engine, a throttle in said pipe, a valve in saidpipe to control the flow of carbureted air to the engine, fuel ignitionmeans in said pipe beyond said valve, a second pipe connected to thefirst pipe beyond the throttle valve and leading to the engine, athrottle in said second pipe to control the flow of carbureted airtherethrough, a valve in said second pipe to control the flow ofcarbureted air to the engine, a governor operated from the engine andcontrolling the second throttle in accordance with the speed of theengine, and a second fuel ignition means at the engine beyond the end ofthe said second pipe.

11. In combination with a two cycle internal combustion engine, acarburetor, a blower to draw air through the carburetor, a pipe leadingfrom the blower to the engine, a throttle in said pipe, a valve in saidpipe to control the flow of carbureted air to the'engine, a second pipeconnected to the first pipe beyond the throttle valve and leading to theengine, a throttle in said second pipe to control the flow of carburetedair therethrough, and a valve in said second pipe to control the flow ofcarbureted air to the engine.

12. In combination with a two-cycle internal combustion engine, acarburetor, a blower to draw air through the carburetor, a pipe leadingfrom the blower to the engine, a throttle in said pipe, a valve in saidpipe to control the flow of carbureted air to the engine, a second pipeconnected to the first pipe beyond the throttle valve and leading to theengine, a throttle in said second pipe to control the flow of carburetedair therethrough, a valve in said second pipe to control the flow ofcarbureted air to the engine, and means to control said second throttlein accordance with the speed of the engine. 7

13. In combination with a two-cycle internal combustion engine, acarburetor, a blower to draw air through the carburetor, a pipe leadingfrom the blower to the engine, a throttle in said pipe, a valve in saidpipe to controlthe flow of carbureted air to the engine, a second pipeconnected to the first pipe beyond the throttle valve and leading to theengine, a throttle in said second pipe to control the flow of carburetedair therethrough, a valve in said second pipe to control the flow ofcarbureted air to the engine, and a governor operated from the engineand controlling the second throttle in accordance with the speed of theengine.

14. In a two-cycle engine having an interrelated blower and acarburetor, an intake pipe leading from the blower to the combustionchamber of the engine, means to control the flow of fuel through saidpipe, a spark plug immediately beyond said means, a second intake pipeleading from the blower to the engine, said second pipe delivering fuelto the engine beyond the spark plug, a throttle in said second pipe tocontrol the flow of fuel therethrough, and single means to control theflow of fuelthrough both pipes.

. CHARLES F. .HTI'IERING.

